Reputation: 11
Can someone maybe help me with the following error. Exception in thread main java.lang.arrayindexoutofboundsexception : 3 at RowTrans.encrypt(Rowtrans.java:33) at RowTrans.main(Rowtrans.java :7)
In my program I want to get a text. Put it in a matrix with 5 columns and determine the rows according to the length of the text. Then i want to change the column and row position so that the row gets the columns position and the column the row. And when a row does not contain 5 values I want to add the character Z in the empty spaces. Can anyone assist me on this error please.
Here is my code
import java.util.Scanner;
public class ColTrans {
public static void main(String[] args)
{
String ori = "This is my horse";
String enc = encrypt(ori);
System.out.println(enc);
// String dec = decrypt(enc);
// System.out.println(dec);
}
static String encrypt(String text)
{
String result = "";
text = text.toUpperCase();
int length = text.length();
int rows = length / 5;
char[][] b = new char[rows][5];
char[][] c = new char[5][rows];
char[] d = new char[length];
if ((length % 5) != 0)
rows = rows + 1;
int k = 0;
for (int i = 0; i < rows; i++)
for (int j = 0; j < 5; j++)
{
if (k > length)
b[i][j] = 'Z';
else
{
d[k] = text.charAt(k);
b[i][j] = d[k];
}
k++;
}
for (int i = 0; i < 5; i++)
for (int j = 0; j < rows; j++)
{
c[i][j] = b[j][i];
result = result + c[i][j];
}
return result;
}
}
Upvotes: 0
Views: 755
Reputation: 69
Here is the cause:
You are increamenting row variable by one, once you have defined the array.
Move following line before line char [][] b =new char[rows][5];
if ((length % 5) != 0)
rows = rows + 1;
Upvotes: 1
Reputation: 2079
According to your description:
text = text.toUpperCase();
char[] b = text.toCharArray();
char[][] c = new char[b.length][5];
int bLen = 0;
for (int i = 0; i < c.length; i++) {
for (int j = 0; j < 5; j++) {
if(bLen < b.length)
c[i][j] = b[bLen++];
else
c[i][j] = 'Z';
}
}
//change the column and row position
char[][]d = new char[c[0].length][c.length];
for (int i = 0; i < d.length; i++) {
for (int j = 0; j < d[0].length; j++) {
d[i][j] = c[j][i];
}
}
Output: TI EZZZZZZZZZZZZHSHZZZZZZZZZZZZZI OZZZZZZZZZZZZZSMRZZZZZZZZZZZZZ YSZZZZZZZZZZZZZ
Upvotes: 0
Reputation: 17401
just change your code as following:
if ((length % 5) != 0)
rows = rows + 1;
char[][] b = new char[rows][5];
char[][] c = new char[5][rows];
char[] d = new char[length];
Upvotes: 0
Reputation: 2563
There are 2 issues in your code. First move the mod part before the matrix instantiation :
if ((length % 5) != 0)
rows = rows + 1;
char [][] b =new char[rows][5];
[...]
Then change if ( k > length )
to if ( k >= length )
Upvotes: 0